Merge branch 'master' into compile-with-jdk-9

* master:
  Fix Gradle wrapper usage on Windows when building BWC (elastic#28146)
  [Docs] Fix some typos in comments (elastic#28098)

Author: jasontedor

core/src/main/java/org/elasticsearch/action/search/TransportSearchAction.java

@@ -313,7 +313,7 @@ private void executeSearch(SearchTask task, SearchTimeProvider timeProvider, Sea
 
         // optimize search type for cases where there is only one shard group to search on
         if (shardIterators.size() == 1) {
-            // if we only have one group, then we always want Q_A_F, no need for DFS, and no need to do THEN since we hit one shard
+            // if we only have one group, then we always want Q_T_F, no need for DFS, and no need to do THEN since we hit one shard
             searchRequest.searchType(QUERY_THEN_FETCH);
         }
         if (searchRequest.isSuggestOnly()) {
@@ -338,8 +338,8 @@ private void executeSearch(SearchTask task, SearchTimeProvider timeProvider, Sea
         if (searchRequest.isMaxConcurrentShardRequestsSet() == false) {
             // we try to set a default of max concurrent shard requests based on
             // the node count but upper-bound it by 256 by default to keep it sane. A single
-            // search request that fans out lots of shards should hit a cluster too hard while 256 is already a lot
-            // we multiply is by the default number of shards such that a single request in a cluster of 1 would hit all shards of a
+            // search request that fans out lots of shards should hit a cluster too hard while 256 is already a lot.
+            // we multiply it by the default number of shards such that a single request in a cluster of 1 would hit all shards of a
             // default index.
             searchRequest.setMaxConcurrentShardRequests(Math.min(256, nodeCount
                 * IndexMetaData.INDEX_NUMBER_OF_SHARDS_SETTING.getDefault(Settings.EMPTY)));

core/src/main/java/org/elasticsearch/search/SearchService.java

@@ -855,7 +855,7 @@ private void parseSource(DefaultSearchContext context, SearchSourceBuilder sourc
 
     /**
      * Shortcut ids to load, we load only "from" and up to "size". The phase controller
-     * handles this as well since the result is always size * shards for Q_A_F
+     * handles this as well since the result is always size * shards for Q_T_F
      */
     private void shortcutDocIdsToLoad(SearchContext context) {
         final int[] docIdsToLoad;

distribution/bwc/build.gradle

@@ -17,6 +17,7 @@
  * under the License.
  */
 
+import org.apache.tools.ant.taskdefs.condition.Os
 import org.elasticsearch.gradle.LoggedExec
 import org.elasticsearch.gradle.Version
 
@@ -118,31 +119,31 @@ if (project.hasProperty('bwcVersion')) {
   task buildBwcVersion(type: Exec) {
     dependsOn checkoutBwcBranch, writeBuildMetadata
     workingDir = checkoutDir
-    executable = new File(checkoutDir, 'gradlew').toString()
     if (project.rootProject.ext.runtimeJavaVersion == JavaVersion.VERSION_1_8 && ["5.6", "6.1"].contains(bwcBranch)) {
       /*
        * If runtime Java home is set to JDK 8 and we are building branches that are officially built with JDK 8, push this to JAVA_HOME for
        * these builds.
        */
       environment('JAVA_HOME', System.getenv('RUNTIME_JAVA_HOME'))
     }
-    final ArrayList<String> commandLineArgs = [
-            ":distribution:deb:assemble",
-            ":distribution:rpm:assemble",
-            ":distribution:zip:assemble",
-            "-Dbuild.snapshot=${System.getProperty('build.snapshot') ?: 'true'}"]
+    if (Os.isFamily(Os.FAMILY_WINDOWS)) {
+      executable 'cmd'
+      args '/C', 'call', new File(checkoutDir, 'gradlew').toString()
+    } else {
+      executable new File(checkoutDir, 'gradlew').toString()
+    }
+    args ":distribution:deb:assemble", ":distribution:rpm:assemble", ":distribution:zip:assemble", "-Dbuild.snapshot=${System.getProperty('build.snapshot') ?: 'true'}"
     final LogLevel logLevel = gradle.startParameter.logLevel
     if ([LogLevel.QUIET, LogLevel.WARN, LogLevel.INFO, LogLevel.DEBUG].contains(logLevel)) {
-      commandLineArgs << "--${logLevel.name().toLowerCase(Locale.ENGLISH)}"
+      args "--${logLevel.name().toLowerCase(Locale.ENGLISH)}"
     }
     final String showStacktraceName = gradle.startParameter.showStacktrace.name()
     assert ["INTERNAL_EXCEPTIONS", "ALWAYS", "ALWAYS_FULL"].contains(showStacktraceName)
     if (showStacktraceName.equals("ALWAYS")) {
-      commandLineArgs << "--stacktrace"
+      args "--stacktrace"
     } else if (showStacktraceName.equals("ALWAYS_FULL")) {
-      commandLineArgs << "--full-stacktrace"
+      args "--full-stacktrace"
     }
-    args = commandLineArgs
     doLast {
       List missing = [bwcDeb, bwcRpm, bwcZip].grep { file ->
         false == file.exists()